Ultrahigh performance cooling is one of the important needs of many industries. However, low thermal conductivity is a primary limitation in developing energy-efficient heat transfer fluids that are required for cooling purposes. Nanofluids are engineered by suspending nanoparticles with average sizes below 100 nm in heat transfer fluids such as water, oil, diesel, ethylene glycol, etc. Innovat...

The cooling system of an Automobile plays an important role in its performance, consists of two main parts, known as radiator and fan. Improving thermal efficiency of engine leads to increase the engine's performance, decline the fuel consumption and decrease the pollution emissions. Water and ethylene glycol as conventional coolants have been widely used in radiators of an automotive industry ...

Single staggered is a design development of normal wire and tube heat exchanger that wires are welded with staggered configuration on two sides. Capacity of wire and tube heat exchanger is the ability of the heat exchanger to release heat. The objective of this study is to analyse the effect of wire pitch (pw) on capacity of single staggered wire and tube heat exchanger. The research...

Increasing interests have been paid to nanofluids because of the intriguing heat transfer enhancement performances presented by this kind of promising heat transfer media. We produced a series of nanofluids and measured their thermal conductivities. In this article, we discussed the measurements and the enhancements of the thermal conductivity of a variety of nanofluids. The base fluids used in...

The objective of this study is to numerically investigate the convective heat transfer of water-based Al2O3 nanofluids flowing through a square cross-section duct with a constant heat flux under laminar flow conditions. The effects of nanoparticle concentration and Peclet number on the heat transfer characteristics of Al2O3-water nanofluids are investigated. The nanoparticle diameter is 25 nm a...

In this research, heat transfer enhancement and simultaneous effect of that on pressure drop inside condensers with twisted tape inserts are investigated. A refrigeration system is designed for attaining to maximum level of heat transfer with minimum pressure drop. The test condenser is a double pipe heat transformer with inner and outer diameter of 10.7mm and 12.7mm for internal pipe, respecti...

Nanofluids are solutions of a small fraction of suspended nanoparticles in a bulk fluid. Nanofluids have shown great promise as heat transfer fluids over typically used bulk fluids and fluids with micron sized particles. The nanoparticles do not settle in the fluid and do not cause clogging or damage to surfaces as with micron sized particles. In the current work we compare the performance of d...

Fouling of the inside of tubes in crude oil preheat systems increases pressure drop and pumping costs. In this paper, a method is proposed for optimizing crude oil velocity to reduce fouling of the heat exchanger tubes thereby maintaining heat transfer rates and reducing pressure drop. A simulated annealing algorithm is proposed to describe and optimize the interactions between heat transfer, p...

This paper investigates the application of thermoelectric devices to enhance the performance of conventional vapor compression based air conditioning systems. Thermoelectric devices are capable of converting electrical energy into thermal heat-pumping at a very high efficiency. In this paper, a validated air-cooled heat exchanger simulation tool is used to study the effect of adding thermoelect...